A thickness detecting mechanism is usually used for measuring the thickness of a paper or a sheet-like article. According to the thickness measured by the thickness detecting mechanism, the further operation will be adjusted. Generally, the thickness detecting mechanism is applied to an electronic device for expanding the function of the electronic device or achieving other functions.
For example, the thickness detecting mechanism could be mounted in a paper shredder. By the paper shredder, a paper is cut into strips or fine particles in order to protect the confidential information of the paper from being stolen. Conventionally, the paper shredder comprises a shredding path, a shredding knife assembly and a thickness detecting mechanism. The shredding knife assembly is disposed at the outlet of the shredding path for cutting the paper that is exited from the shredding path. The thickness detecting mechanism is disposed beside the shredding path for detecting the paper that is transported through the shredding path.
During operation of the paper shredder, the thickness detecting mechanism could discriminate whether the paper introduced into the paper shredder is beyond an acceptable limit of the paper shredder by detecting the thickness of the paper.
In a case that the thickness of the paper is not beyond the acceptable limit, the operation of the paper shredder is continuously done. Whereas, in a case that the thickness of the paper is beyond the acceptable limit, the operation of the paper shredder is interrupted or the paper is withdrawn from the paper shredder in order to prevent from damage of the paper shredder. Various thickness detecting mechanisms applicable to the conventional paper shredder have been disclosed in for example US Patent Publication No. US2006/0219827A1, and the contents of which are hereby incorporated by reference.
In addition, the thickness detecting mechanism could be applied to a sheet laminating apparatus. The sheet laminating apparatus is used for laminating a valuable sheet-like article between two pieces of protective films in order to achieve the protective purpose. Conventionally, the sheet laminating apparatus comprises a transfer passage, a heat-treating member, a laminating member and a thickness detecting mechanism. The sheet-like article could be transported through the transfer passage. The thickness detecting mechanism is disposed beside the transfer passage. The laminating member is arranged at the distal end of the transfer passage. The laminating member is enclosed by the heat-treating member for converting electrical energy into heat energy. The heat energy is transmitted to the laminating member to heat up the sheet-like article, and the sheet-like article is pressed by the laminating member.
As known, the performance of the sheet laminating apparatus is influenced by the thickness detecting mechanism, because the thickness of the sheet-like article is highly dependent on the working temperature of the heat-treating member and the rotating speed of the laminating member. Generally, as the thickness of the sheet-like article is increased, the heat energy required by the sheet laminating apparatus is increased. That is, the working temperature of the heat-treating member is increased. In addition, the rotating speed of the laminating member needs to be reduced in order to increase the residence time of the sheet-like article in the sheet laminating apparatus and absorb much heat energy. On the other hand, as the thickness of the sheet-like article is decreased, the working temperature of the heat-treating member is decreased and/or the rotating speed of the laminating member is increased. In other words, the thickness detecting mechanism is required for operating the sheet laminating apparatus. According to the thickness of the sheet-like article measured by the thickness detecting mechanism, the working temperature of the heat-treating member and the rotating speed of the laminating member are dynamically controlled.
From the above discussion, it is found that the thickness detecting mechanism is very important for many electronic devices. Since the conventional thickness detecting mechanism has complicated mechanical configurations, the fabricating cost thereof is very high. In addition, since there are too many components included in the conventional thickness detecting mechanism, the assembling process thereof is complicated. In other words, the conventional thickness detecting mechanism is not cost-effective.
Therefore, there is a need of providing a cost-effective thickness detecting mechanism so as to obviate the drawbacks encountered from the prior art.